Interface for all servlets
Authentication asks: who is the user.
Authorization asks: what is the user allowed to do? This class holds user rights.
Users or technical clients of the user are represented with Objects of this class.
Helper class to provide BufferedReader Objects for get and post connections
A credential is used as key in DAO.authentication
an identity is only a string which contains details sufficient enough to identify a user and to send data to that user
Storage of a peer list which can be used for peer-to-peer communication.
wrapper class for the result type of services: either JSONObject, JSONArray, String, or byte
Accounting asks: what has the user done.
A UserRole defines the servlet access right.